I have an 87 blazer 2.8 carberated. It started to die when I came to a stop light and had to gas it with my foot on the brake to keep it from stalling. This I had to do till I got it home and it would not start. I had a har time pulling the codes but the only one I got was mass rir sensor and replaced it. I did a complpete tune up and still can't get it started. I bench tested the EGR and checked the vacume system as much as you can with out it running. It just spits and puffs. The fuel pump kicks in and I'm getting spark and I have 4 times rechecked the proper plug wire to distributer. on the distributor #1 @ 6:30 and fireing order 123456 #1-3 on the pass side, 2-6 driver side. #1,#2 are the front cylinders.. I checked each vavuum hose and cleaned the EVR and EGR from possable carbon build up. I Though timming belt but thwere is no back fire and there is only one person to turn it over and check timing on the crank. Any help would be appreciated. Tom